Efficient delivery of the immunodominant genes of African swine fever virus by adeno-associated virus serotype 2

Background and Aim

Adeno-associated virus serotype 2 (AAV2) represents a promising basis for developing a virus-vector vaccine against African swine fever (ASF). This study aimed to create genetic constructs based on AAV2 to deliver the immunodominant genes of ASF virus (ASFV) and to evaluate their functionality in vitro. The efficiency and specificity of transgene expression, as well as their non-toxicity in cells of target animals, were evaluated.

Materials and Methods

Bioinformatics analysis methods were used to identify the immunodominant genes of ASFV. The target genes B646L, E183L, CP204L, and CP530R were identified and subsequently cloned into the pAAV-MCS vector. Assembly of recombinant AAV2 (rAAV2) was performed by cotransfection of AAV293 cells with the following plasmids: pAAV-MCS with the gene of interest, envelope, and packaging. Quantitative polymerase chain reaction was used to determine the AAV2 titer. The functionality of the constructs was evaluated in HEK293 and SPEV cells by determining the presence of mature proteins in the cell lysate and the expression levels of messenger RNA. The specificity of the target proteins in cell lysates was confirmed by Western blotting.

Results

The proposed AAV2 assembly protocol makes it possible to achieve a concentration of mature viral particles of at least 280 billion/mL of virus-containing material. The rAAV2 could effectively transduce host SPEV cells. The expression of both cistrons was detectable during the transduction of cells; therefore, the combined expression of immunogens in the cells of target animals should be possible using this method.

Conclusion

This study demonstrated the potential of using genetic constructs based on AAV2 for the delivery of ASFV genes in vitro.

Artificial Microvesicles: New Perspective on Healing Tendon Wounds

Tendons have a limited capacity to repair both naturally and following clinical interventions. Damaged tissue often presents with structural and functional differences, adversely affecting animal performance, mobility, health, and welfare. Advances in cell therapies have started to overcome some of these issues, however complications such as the formation of ectopic bone remain a complication of this technique. Regenerative medicine is therefore looking toward future therapies such as the introduction of microvesicles (MVs) derived from stem cells (SCs). The aim of the present study was to assess the characteristics of artificially derived MVs, from equine mesenchymal stem cells (MSCs), when delivered to rat tendon cells in vitro and damaged tendons in vivo. The initial stages of extracting MVs from equine MSCs and identifying and characterizing the cultured tendon stem/progenitor cells (TSCs) from rat Achilles tendons were undertaken successfully. The horse MSCs and the rat tendon cells were both capable of differentiating in 3 directions: adipogenic, osteogenic, and chondrogenic pathways. The artificially derived equine MVs successfully fused with the TSC membranes, and no cytotoxic or cytostimulating effects were observed. In addition, co-cultivation of TSCs with MVs led to stimulation of cell proliferation and migration, and cytokine VEGF and fractalkine expression levels were significantly increased. These experiments are the first to show that artificially derived MVs exhibited regeneration-stimulating effects in vitro, and that fusion of cytoplasmic membranes from diploid cell lines originating from different species was possible. The experiment in vivo demonstrated the influence of MVs on synthesis of collagen I and III types in damaged tendons of rats. Explorations in vivo showed accelerated regeneration of injured tendons after introduction of the MVs into damaged areas. The results from the studies performed indicated obvious positive modifying effects following the administration of MVs. This represents the initial successful step required prior to translating this regenerative medicine technique into clinical trials, such as for tendon repair in injured horses.

Personal autonomy development and family functioning of Russian and Azerbaijan adolescents

Introduction

The development of adolescent’s autonomy is influenced by both: family and culture. Cross-cultural studies show different autonomy development trajectories and culture-specific family organization tendencies. The comparison of autonomy development in different cultures can help in clarifying universal and culture-dependent aspects of autonomy development.

Objectives

The present research studies adolescent’s autonomy in context of family functioning in Azerbaijani (Baku) and Russian (Moscow) adolescents.

Methods

Family Environmental Scale (FES), Method of unfinished sentences to study adolescent’s autonomy fields («I feel independent when…»), The Separation-Individuation Test of Adolescence (SITA) were used in the study with 201 adolescents, aged from 13 to 18.

Results

Family functioning of adolescents from Moscow is less achievement oriented (U-test, p=0,000), family life is less organized (p=0,000) and controlling (p=0,000). Adolescents in Baku consider the value of independence in families higher (p=0,01).

Context analysis of unfinished sentences shows universal categories of autonomy representation (autonomy in specific activities, autonomy as possibility to be alone) and culture specific representations: adolescents from Moscow describe autonomy more like «independence from others», whereas adolescents from Baku describe autonomy as «the presence of others nearby».

Engulfment Anxiety shows negative correlations (р<0,01) with family cohesion (r=0, -0,474), conflict (r=-0,466) and independence (r=-0,326) for all adolescents, with expressiveness (r=-0,490) and achievement orientation(r=-0,286) by Moscow adolescence and with intellectual-cultural (r=-0,249) and recreational family orientation (r=-0,278) by Baku adolescents.

Conclusions

Autonomy development in families has universal aspects (positive effects of cohesion, etc.), but Moscow adolescents are less focused on others and family in their autonomy development.

Disclosure

No significant relationships.

Loneliness in adolescents with different social media behavior

Introduction

Loneliness is a critical issue of adolescents that has grown severe during the last decade. Social media use is often regarded as negative factor of loneliness experience in connection with escapism. At the same time social media is an important part of adolescents’ communication sphere. The present study aims to explore positive functions of social media which can help adolescents cope with loneliness.

Objectives

The present research studies features of loneliness representation in adolescents with different behavior in social media.

Methods

Multidimensional Inventory of Loneliness Experience; Cognitive Processing of Social Information in Internet Questionnaire; Method of unfinished sentences about loneliness and social media; Questionnaire about social media were used in the study with 44 adolescents, aged from 13 to 18.

Results

Adolescents have a higher level of loneliness (M = 29.6) than the results in 2013 (M = 17.7) show. Context analysis of unfinished sentences shows that 21% of adolescents have a various representation of loneliness, 71% perceive loneliness as negative. General feel of loneliness tends to show negative correlations with adequate perception of information in social media (k = - 0.317; p = 0.038). Negative attitude to loneliness is negatively correlated with interpretation adequacy of social media content (k=-0.568, p<0,001). Adolescents with low levels of holistic social media perceptions have higher levels of loneliness. Use of social media can reduce feelings of loneliness (p = 0.002).

Conclusions

Social media expand adolescents’ representation of loneliness. Productive use of social media can help adolescent cope with loneliness.

Disclosure

No significant relationships.

Improving Culture Conditions, Proliferation, and Migration of Porcine Mesenchymal Stem Cells on Spinal Cord Contusion Injury Model in vitro

Adipose tissue-derived mesenchymal stem cells (AD-MSCs) are promising for cell therapy in spinal cord injury (SCI). The pig is one of the most approximate models of many human diseases, including SCI. In our study, we selected the optimal conditions for the culture of porcine AD-MSCs and developed an in vitro SCI model based on the culture of cells in injured spinal cord extracts (SCE) 3 days and 6 weeks after SCI. We show that Dulbecco's Modified Eagle Medium (DMEM) with 20% serum content, supplemented with a combination of 5 mM L-ascorbate-2-phosphate and nonessential amino acids, stimulated a typical fibroblast-like morphology and high proliferation of porcine AD-MSCs. SCE caused a higher proliferation of porcine AD-MSCs compared with extracts from an intact spinal cord. The optimal proliferating effect was achieved using rostral 3 days SCE, and proliferation was lower in caudal and central SCE. Porcine AD-MSCs migration to the 3 days and 6 weeks SCE was higher than to an intact one and preferred the rostral SCE, avoiding central and caudal SCE. We also studied 13 cytokines contained in SCE but did not observe any definite relationship between some analyte concentrations and a change in the behavior of AD-MSCs.

The treatment of articular cartilage injuries with mesenchymal stem cells in different animal species

One of the major problems observed in veterinary practice is articular cartilage injuries in animals. In terms of agriculture, it leads to their culling from the herd, even if they are highly productive animals. With companion animals, owners usually have to decide between euthanasia or long-term sometimes lifelong treatment of the injury by a veterinarian. The use of mesenchymal stem cells (MSCs) for the treatment of cartilage injury in veterinary medicine is based on the good results observed in preclinical studies, where large animals have been used as experimental models to study the regenerative activity of MSCs. According to the literature, MSCs in veterinary medicine have been used to treat cartilage injury of dogs and horses, whereas sheep and goats are generally models for reproducing the disease in preclinical experimental studies.

Application of gene therapy in the treatment of superficial digital flexor tendon injury in horses

Background:

Tendon injuries are one of the most common causes of orthopedic disorders in horses. Such injuries involve a long course of treatment and recovery. The most promising method of treating these injuries is the use of recombinant proteins and gene therapy.

Aim:

In this work, we evaluated the therapeutic efficacy of plasmid DNA (pDNA) containing two species-specific coding sequences, i.e. vascular endothelial growth factor 164 (VEGF164) and fibroblast growth factor 2 (FGF2), in the treatment of severe damage to the tendon of the superficial digital flexor.

Methods:

A pDNA construct was used to restore the damaged superficial digital flexor tendon in the horse.

Results:

This study showed that the administration of pDNA encoding VEGF164 and FGF2 genes at the injury area increased the regenerative activities of the damaged tendon.

Conclusion:

This study shows the therapeutic properties of genetic constructs (pDNA) and contributes to the advancements in the use of these therapies.

Mesenchymal Stem Cell Therapy for Spinal Cord Contusion: A Comparative Study on Small and Large Animal Models

Here, we provide a first comparative study of the therapeutic potential of allogeneic mesenchymal stem cells derived from bone marrow (BM-MSCs), adipose tissue (AD-MSCs), and dental pulp (DP-MSCs) embedded in fibrin matrix, in small (rat) and large (pig) spinal cord injury (SCI) models during subacute period of spinal contusion. Results of behavioral, electrophysiological, and histological assessment as well as immunohistochemistry and real-time polymerase chain reaction analysis suggest that application of AD-MSCs combined with a fibrin matrix within the subacute period in rats (2 weeks after injury), provides significantly higher post-traumatic regeneration compared to a similar application of BM-MSCs or DP-MSCs. Within the rat model, use of AD-MSCs resulted in a marked change in: (1) restoration of locomotor activity and conduction along spinal axons; (2) reduction of post-traumatic cavitation and enhancing tissue retention; and (3) modulation of microglial and astroglial activation. The effect of an autologous application of AD-MSCs during the subacute period after spinal contusion was also confirmed in pigs (6 weeks after injury). Effects included: (1) partial restoration of the somatosensory spinal pathways; (2) reduction of post-traumatic cavitation and enhancing tissue retention; and (3) modulation of astroglial activation in dorsal root entry zone. However, pigs only partially replicated the findings observed in rats. Together, these results indicate application of AD-MSCs embedded in fibrin matrix at the site of SCI during the subacute period can facilitate regeneration of nervous tissue in rats and pigs. These results, for the first time, provide robust support for the use of AD-MSC to treat subacute SCI.

Allogenic Adipose Derived Stem Cells Transplantation Improved Sciatic Nerve Regeneration in Rats: Autologous Nerve Graft Model

We examined the effect of transplantation of allogenic adipose-derived stem cells (ADSCs) with properties of mesenchymal stem cells (MSCs) on posttraumatic sciatic nerve regeneration in rats. We suggested an approach to rat sciatic nerve reconstruction using the nerve from the other leg as a graft. The comparison was that of a critical 10 mm nerve defect repaired by means of autologous nerve grafting versus an identical lesion on the contralateral side. In this experimental model, the same animal acts simultaneously as a test model, and control. Regeneration of the left nerve was enhanced by the use of ADSCs, whereas the right nerve healed under natural conditions. Thus the effects of individual differences were excluded and a result closer to clinical practice obtained. We observed significant destructive changes in the sciatic nerve tissue after surgery which resulted in the formation of combined contractures in knee and ankle joints of both limbs and neurotrophic ulcers only on the right limb. The stimulation of regeneration by ADSCs increased the survival of spinal L5 ganglia neurons by 26.4%, improved sciatic nerve vascularization by 35.68% and increased the number of myelin fibers in the distal nerve by 41.87%. Moreover, we have demonstrated that S100, PMP2, and PMP22 gene expression levels are suppressed in response to trauma as compared to intact animals. We have shown that ADSC-based therapy contributes to significant improvement in the regeneration.